This article seeks to enhance our understanding of the European Parliament (EP) elections in an era of populist and anti-European Union (EU) politics. Specifically, it aims to evaluate both the conventional second-order elections theory as well as an alternative approach that regards EP elections as an arena for conflict between liberal-democratic Europeanism and populist, extremist and euroskeptic alternatives. It does so by deriving a series of hypotheses from both approaches and testing these with party-level data from all EU member states in the context of 2019 EP elections. Our results challenge both explanations. Party size is a robust predictor of electoral performance in EP elections, and its effect is moderated by electoral system design. While large parties lost votes across the EU, their losses were more pronounced in countries where national legislatures are elected under plurality or mixed systems. We find no evidence of incumbent losses or electoral cycle effects. Party-level populism, extremism and euroskepticism did not systematically predict electoral performance but party ideology appears to have moderated the effects of incumbency and party size. Incumbency was associated with vote gain among populist and far-right parties but not other parties, and the effect of size also varied across party ideologies. In sum, these results suggest that vote fragmentation in the 2019 EP elections is partly explained by electoral system design, while it was not driven by the desire to punish political incumbents. Populist and far-right parties in power appear to be particularly immune to punishing behavior often associated with EP elections.